Is this rim safe to ride on?
 

So my friend's Sirrus was vanadlized and he went and bough a new bike. I salvaged some parts from it, including the wheels. They are true enough, a little bit of wobble but nothing that 10 minutes in a truing stand couldn't fix. I was looking at the wheels a bit more closely and I noticed that the back wheel has a small dent in the rim

http://farm4.static.flickr.com/3302/...ac8f916a_m.jpg

Is this rim still safe to ride?

Thanks!

Safe? Sure, but the brakes will probably grab whenever that dent passes the brake pads. Depending on the rim, that might be fixable. Your LBS might have a tool like this that can squeeze it back into shape:

http://www.biketoolsetc.com/Product_Images/BR-RS1.jpg

Hard to tell exact severity from the photo, but probably millions of bikes being ridden at this moment with rims worse than that. I don't know that I would start a long tour on it but for general riding it should be O.K. Likely be more of an annoyance than a safety issue. Could have future possible tire issues at that area possibly.
I'd ride it.

Assistant TO the Regional Manager...

Anyways, I would make sure that the dent didn't cause a burr or a sharp edge on the inside of the rim, but it looks fine - though will never be as strong as it used to be.

I've fixed a zillion rims that have a ding like that. That tool that John pictured above is ideal. If you don't have access to one, bang the rim back into shape with a ball-peen hammer, using a block of wood on the other side to limit your banging. Use a straight-edge to check your work.

You probably won't get it perfect, but you can improve it.

Or, use a big adjustable wrench to grip the lip that is bulged out and gently bend it back. Then take a file and file the braking surface flat so the brakes don't catch.

This is what I would do before riding it.

Also make sure there aren't any hairline fractures on the top of the rim around the spoke nipples. That would be very unsafe.

+1 The above is unlikely, but you really don't want to be riding on it if you find any. Other than that you should be fine. I've ridden worse.

Since you have nothing to lose you can attempt to straighten it.
I've done similar jobs using a large cresent/adjustable wrench
in small increments work from the center of the bend with the jaws closed as much as possible around the rim. Any burrs can be sanded with #400 emery cloth.

If you don't have this gizmo, channellock pliers might work if the bulge isn't too long.

http://tbn1.google.com/images?q=tbn:...s/15888_lg.jpg

You can accomplish the same thing with a large channel pliers or a very large vise-grip. You have to be very careful to only apply the right amount of force no matter what tool you use.

If its an aluminum rim, check carefully for cracks or blemishes where the bend and re-bend occurred.

This is one occasion where steel rims are preferable. They're easier to bend back in shape.

no,its not safe!
Only after your braking surface is completely smooth, trued...
If not, you will probably adjust your brake pads to avoid friction with the dent, which in turn will DIMINISH your ability to stop ...
and that is Very Unsafe!
That said, your braking surface has to be smooth.
The smoother the better.